Do it in C please.

*The parseint ) function parses a well-formed string representation of * an integer (one which would return true from isinteger )) and returns the integer value represented by the string. For example, the string "1234" would return the value 1234. This function does not need to *handle badly-formed strings in any particular fashion, its operation *on badly-formed strings is undefined. Returns the integer value stored in the given string nt parseint (char *str)